Textile treating solutions and compositions containing same



Patented Oct. 9, 1951 TEXTILE TREATING SOLUTIONS AND COMPOSITIONS CONTAINING SAME Frank Wesley Lane, Newport, and William Leonard Dills, Wilmington, DeI., assignors to E. I. du Pont de Nemours & Company, Wilmington, DeI., a corporation of Delaware No Drawing.

Application January 24, 1947,

Serial No. 724,242

Claims. 1

This invention relates to new titanium-antimony compositions useful in treating cellulosic substances, especially textile materials, in order to impart valuable properties thereto. More particularly. it relates to the production of novel, relatively dilute, stable, monobasic acid solutions containing titanium and antimony useful for imparting flame-proof characteristics to textiles having a cellulosic base.

The cellulosic fabrics of commerce such as rayon and cotton goods are easily ignited in the presence of a flame, and when used in clothing of very light weight, or of heavier weight but having a pile finish, present appreciable fire hazards to the wearer. Pile fabrics areparticularly disadvantageous in this respect because the cellulosic pile propagates a flame easily. As a consequence, clothing manufacture from these fabrics has been somewhat retarded in the trade despite the more attractive appearance which they present. This dangerous characteristic is so great that action by the American Association of Textile Chemists and Colorists has resulted in its providing a testing method for such fabrics to determine their flash or flame-resistance properties." In such test, a rectangle of the treated cloth, measuring 2" by 6", must be heated for minutes at 105 C. and then cooled in a desiccator over calcium chloride. The resulting dried cloth must have a moisture content of less than .3%. The cooled cloth must then be removed while supported on a screen held at a 45 angle, and must be touched with a half-inch flame. To pass such test, even after' laundering, pile goods must not show material flashing, while fiat goods (tested in a vertical position) must not continue to burn after the flame is removed.

Various oxides have been added to or incorporated in fabrics to render them fireor flameproof. Processes employed for the purpose usually included the simultaneous use of a chlorinated resin or chlorinated parafiin to assist in obtaining the flame-proofing effect sought. Such methods, however, substantially change the nature of the goods under treatment by reason of the resin or parafiin addition, which disadvantageously alters the properties of the fabric and limits the extent of use of the fiame-proofed ma terial. Hence, fabrics so treated are not satisfactory for general clothing purposes. Furthermore, such treatment cannot be applied to pile goods, nor, following treatment, can the pile be easily raised on the fiat goods. As a consequence,

' ing in consumer appeal, while untreated products,

prior flame-proofed fabrics have not proved acceptable to clothing manufacturers because lack-- goods having a high pile whlch will meet all such as those made of cotton and rayon and particularly pile fabrics made from brushed viscose rayon, although possessing requisite consumer appeal, have met with resistance due to their substantial fire hazard risk.

Antimony solutions have also been used to treat textile materials, but these must be employed at such high concentrations of acidity that they become disadvantageous for use in treating certain textiles, particularly delicate cellulosic substances, due to the deleterious, injurious effects which they exert thereon. Relatively dilute solutions, on the other hand, are nonuseful because unstable in nature and decompose to prematurely precipitate antimony oxide.

The disadvantages exhibited by prior textile treating solutions have greatly limited their utility in such field, and present a real need for a treating solution which is free from such disadvantages and is effectively useful for treating all forms of cellulosic textile materials, and more especially delicate cellulosic substances.

It is among the objects of this invention to overcome the above and other disadvantages characterizing prior cellulosic textile treating solutions, and to provide in particular a novel form of antimony-titanium monobasic acid solution, which, though in relatively dilute state, remains highly stable and is eminently satisfactory for treating or impregnating cellulosic substances in order to impart flameand flash-resistant characteristics thereto. Further objects include the provision of a novel solution containing as an essential ingredient a dissolved complex titaniumantimony compound and methods for obtaining the same; the provision of a relatively dilute, stable halogen acid (especially chloride) solution of titanium and antimony which is resistant toward decomposition or hydrolysis in the presence of substantial amounts of aqueous media; the provision of a titanium-antimony solution which, when applied to a textile material, will provide a non-toxic, laundry-proof type of product and will be free from the injurious. toxic and other effects attendant the use of antimony solutions upon textiles. A prime objective of the invention is to overcome the hazardous character toward fire which prior cellulosic fabrics employed as clothing have exhibited; while a further object is the production of cellulosic base fabrics which are flash-proof and remain substantially unchanged in appearance and feel after treatment. A still further object is to produce rayon and cotton standards of the rigorous A. A. T. C. C. test above outlined. Other objects and advantages will be apparent from the ensuing description of our invention. 7

These and other objects are realized in this invention which embodies the discovery that certain monobasic acid solutions of titanium and antimony, and more especially halide (chloride) solutions thereof, are eminently useful, even under conditions of relatively high dilution, for treating cellulosic textile materials, and that the treated product results in a flameand flashproofed composition which will meet all requirements of the above A. A. T. C. C. test.

In practically applying the invention in accordance with one particular adaptation thereof, our stable, dilute antimony-titanium solution can be readily obtained by first combining at room temperatures commercial titanium tetrachloride with antimony oxide in the presence of water, and effecting the combination in such manner as will produce a dissolved complex titanium-antimony compound in which, preferably, the acid portion of the complex is supplied by hydrochloric acid and a ratio of 1 mol of HCl for each 2 mols of titanyl chloride and each moi of antimony chloride exists. Thus, titanium tetrachloride is first dissolved in cold water, following which the antimony oxide proportion is added to the resulting aqueous titanium solution, with such proportion of reagents being enployed that the concentration of the oxides of titanium and antimony in the final solution will range, preferably, from 200 to 400 g./l. of the combined titanium and antimony oxides. To insure production of a stable solution free from any tendency to hydrolyze or precipitate antimony oxide, care must be taken to maintain in the solution a concentration of not less than 2.5 to 3 mols of chloride ions over and above those'present in the SbCls. Such solutions exhibit excellent stability characteristics, even when relatively dilute and although they contain less chlorine than is necessary to form the normal chlorides of titanium and antimony, i. e., are basic. This stability is contrary to the characteristics of equivalent solutions in which titanium ions are not present. For commercial purposes and more economical shipping, solutions containing about 400 g./l. of the oxides of titanium and antimony are preferred. Prior to use, they can be readily adjusted to about .300 g./l. of the combined oxides.

As stated, the titanium-antimony solutions of the invention are useful in the treatment of cellulosic substances generally, especially those having hydroxy groups which are free to combine with titanium, and particularly materials, such as wood, cellulosic films, cloth, woven fabrics, paper, cellophane, etc., to impart flameand flash-resistant properties thereto. Our novel solutions are outstandingly ueful in the flameproofing of cellulosic textile materials, including natural cellulose, such as cotton, artificial [silks obtained from regenerated cellulose fibers from either the viscose, cellulose acetate, nitrocellulose or cuprammonium manufacturing processes, wherein use is resorted to of cellulose derivatives,

such as cellulose esters (acetate, formate, bu-* other forms of the textile, including knitted or netted fabrics, threads, yarns, fibers, etc. Advan tageously, the textile, after treatment, though containing substantial amounts of antimony, is non-toxic and harmless in nature, a property in sharp contrast to that exhibited by compositions treated with antimony oxide alone, and which are known to be toxic and harmful in that they cause serious physiological effects after intemai use or external application.

In treating the rayon, cotton, or like textile material with our solution to impart the desired flame-proofing characteristics thereto, it is first wetted by immersing it, for example, in a suitable bath containing the monobasic acid titanium-antimony solution and allowing it to remain therein for a period of time ample to allow the liquid to completely permeate the interstices and pores of such material. Alternatively, the impregnation can be effected by passing the material between suitable rollers suitably coated or wet with the impregnating solution. After such immersion and impregnation, it may be removed from the bath and passed through suitable nip or ringer rolls, or centrifuged, to remove excess treating solution and insure uniform treatment and impregnation throughout. The temperature of the immersing bath is usually maintained at about 25 C., but preferably ranges from 5 C. to C., and should not be allowed to exceed about C., so that no damage to the textile under treatment will take'place. After impregnation, the product is passed into a suitable precipitating bath containing a precipitant capable of precipitating the titanium-antimony complex in insoluble form on the textile material. Among useful precipitants for the purpose are ammonium hydroxide and salts and alkali metal hydrates, as well as salts of the alkali metals. Specific examples of such precipitants include solutions of sodium carbonate, sodium hydroxide, potassium hydroxide, potassium carbonate, ammonium hydroxide, sodium silicate, sodium phosphate, phosphoric acid, benzoic acid, boric acid, etc. The precipitating bath is usually maintained at ordinary room temperature, but may be at higher or at lower temperatures and ranging from 5 C. to C. Preferably, a dilute concentration of the precipitant is maintained in the bath, with solutions at from about 1% to 20% strengths being adequate for most purposes. The time treatment of the textile in the bath is variable and will depend upon its type and thickness.

. Following precipitating bath treatment, the textile is next conventionally washed by passing it through a washing bath containing water or other suitable washing fluid, such as a soap solution, in which by-products of the reaction are removed and any loosely-held metal compounds,.

such as hydrated titanium and antimony oxides,

which are easily removed by laundry treatments To a clearer understanding of the invention, the following specific examples aregiven, which are merely illustrative and not to be taken as limiting the underlying principles or scope of the invention: I

Example-I A titanium chloride solution was prepared by adding titanium tetrachloride to cold water to provide a concentration of 210 g./ 1. TiOz and 382 g./l. HCl. Antimony trioxide was then dissolved in this solution to a concentration of 100 g./l., the "final solution containing antimony oxide to the amount of 48% by weight of the T102 or 26% by weight of the HCl. The resulting product comprised a clear, yellow, homogeneous solution of a titanium-antimony complex, which solution,

though dilute in nature, was highly stable andevidenced no tendency to hydrolyze or reprecipitate the antimony oxide. In contrast thereto, an

equivalent antimony solution containing no tin tanium ions exhibited marked decomposition and hydrolysis, due to water presence.

ExamPZeII A titanyl chloride solution containing 200 g./l. T102 and 365 :/l. HCl (approximately 1 mol of titanium to 4 adding comm rcial titanium tetrachloride to icecold water. Sufdcient antimony trloxide was then dissolved in this to give a concentration of 6.4 grams per liter. This represented an SbzOa content of 3.2% by weight of T102 or 1.75% by weight of-HCl. As in the instance of Example I, a clear, stable, yellow solution was obtained.

Example III Example IV A titanium chloride solution was prepared from anhydrous TiCh by adding the latter to cold water and diluting to 300 g./l. T102 and 497 g./l. HCl. 311203 was then dissolved in the resulting solution and sumcient water was added to give a solution containing 220 g./l. TH): and 165 g./l. SbzOs. As in the instance of the above examples, a clear, stable, yellow solution was also obtained.

Example V A titanium chloride solution was prepared from anhydrous titanium tetrachloride by adding the latter to water under conditions conducive to the evolution of gaseous HCl. The solution thus prepared analyzed 400 grams per liter T102 and 380 grams per liter HCl and contained slightly more than 2 mols of HCl per mol of titanium. This solution was mixed with an equal volume of antimony chloride solution analyzing 400 grams per liter SbzOs. The mixed solution contained 200 grams TlOz per liter and 200 grams per liter SbzOa. Brushed viscose blanket material having to /2" pile was soaked in this solution for 5 minutes, wrung on a tight roll and after minutes immersed in a saturated NazCOa solution until neutral. The material was thorenemy scrubbed with soapy water'and rinsed.-

ols of chlorine) was prepared by I A sample of the treated fabric after air drying for 24 hours was heated for 15 minutes at C. in a circulating oven and cooled to room temperature in a CaCla desiccator. The dried sample supported at a 45 angle, after the pile had been raised with a comb or brush, did not flash when a /z" flame was impinged on its surface for 1 second. The treated sample contained 7.5% T102 and 7.5% SbzOz.

After 20 complete washings in 0.5% Ivory soap flakes solution the treated sample was flash-proof when again tested as described above.

Example VI Cotton sheeting material and flat viscose curtain material were dipped in the solution of Example IV and wrung on a tight roll. After 15 minutes the material was neutralized with saturated NazCOa solution and washed to remove the loosely-held hydrous oxide precipitates. The airdry samples heated 15 minutes at 105 C. and cooled in a CaClz desiccator, held in a vertical position and touched with a half-inch flame did not continue to burn after the flame was removed.

The treated cotton sheeting was tested after'15 washings and was still flame-proof by the A. A. T. C. C. test.

The flat viscose material washed 25 times still passed the flame test described, also demonstrating the laundry-proof character of the treatment.

Although described as applied to certain speciflc adaptations, the invention is not limited thereto. For instance, while hydrochloric acid solutions of antimony and titanium are particularly described and preferred for use, production is generally contemplated of stable, mcnobasic acid solutions containing both antimon and titanium as essential constituents. Thus, in lieu of the chloride, other monobasic acid solutions such as those of nitric acid, or of other halides, such as hydrogen bromide or hydrogen iodide, can be produced and utilized in the flameproofing of textiles, it being essential to these solutions, as in the case of the chloride, that they contain at least 2.5 atoms of the monolcasic anion over and above that presentin the antimony compound, with a concentration of from 2.5 to 5 atoms of said anion over and above said antimony compound comprising a preferred useful concentration. Likewise, although solutions having concentrations of the combined titanium and antimony oxides ranging from 200-400 g./l. are preferred for use, solutions containing concentrations of such combined oxides ranging from 25 to 500 g./l. can also be employed. For commercial usage, solutions containing about 2 mols of titanium chloride for each mol of antimony chloride are most advantageously useful. On a weight basis, this is slightly less of antimony oxide than titanium oxide (.9 SbzOa for each 1 pound of TiOz). This ratio may be varied, if desired, to, say, from .5 part by weight to 1.5 parts by weight of Sb2O3 for each part by weight of TiOz in the solution. While the above comprise the concentrations most useful commercially, the ratio of titanium to the antimony,

using the combined solution generally may vary from 1 part titanium oxide to 1 part of antimony oxide up to about 10 parts titanium oxide to each part of the antimony oxide, with the antimony oxide content of the solution, however, not being permitted to run below about 5 g. l. To avoid any toxic effect by reason of antimony presence, it is also essential that the atom ratio of Sb to Ti not exceed 2. Such solutions will provide sufficient treating agent to yield a treated fabric containing from about 8 to 16% combined metal oxides when applied to viscose goods. Obviously, the actual amount realized will depend on such things as the past history of the fabric, the length of time of contact of the solution With the fabric, the concentrations of solution used, the steps taken to remove excess solution from the fabric, and the like.

Again, while preferably the antimony and titanium complex of this invention is obtained by combining commercial titanium tetrachloride with antimony oxide, SbzOa, in the presence of water, the invention is not limited to such reactants nor to such preferred method of obtaining the complex. Any soluble, monobasic acid salt of antimony and titanium, including their nitrates, chlorides, iodides, and bromides, can be employed in the mixing, as can the'respective oxides of these metals. In utilizing titanium oxide, the T102 can be dissolved in hydrochloric acid followed by dilution with water of the resulting solution to the desired concentration. The titanium oxide combines in this instance with the HCl and forms titanyl chloride, the Ti++ ions of which appear to cause the desired effective stabilization. The quantity of titania used will depend upon the concentrations of the other components of the solution and the results desired, but in general the employment of about r mol of titanium to at least 2 mols of chlorine will usually provide satisfactory results. In addition to SbzOa, other forms of antimony oxide can be used, including the tetra and penta oxides, as well as antimony oxychlorides. When antimony chloride is employed, it can be dissolved in water, provided the solution is acidified by the presence of free HCl, following which the antimony solution can be combined with the titanium solution.

While sodium carbonate comprises a preferred type of mildly-alkaline reagent or precipitant for the treated textile following its treatment with the titanium-antimony solution, other types of alkaline agents, such as sodium bicarbonate, ammonium carbonate, potassium carbonate, etc., may be employed. Similarly, washing of the neutralized fabric with a soap solution can be effected through the use of any type of detergent solution, such as ordinary laundry soaps adequate to remove loosely-adhering metal compounds and effect a desired cleaning of the fabric.

The stability exhibited by the dilute titaniumantimony solution of this invention appears to arise from the association of titanium and antimony ions with each other with resulting formation of a definite complex compound within the solution itself or in the fabric impregnated therewith. This is clearly demonstrable by means of light transmission measurements of a series of solutions consisting of (a) a molar antimony chloride solution containing 3 mols of HCl; (b) a solution containing 2 mols of titanium chloride. designated as a TiOClz solution, containing 3 mols of HCl in excess of that required for the given formula of the titanium salt, but less chlorine than would be present in a solution resulting from the dissolution of TiCh in water; and (c) a combined solution containing 1.mol of SbCla, 2 mols of TiOClz. and, like the other two solutions, 3 mols of 1101. When curves are prepared on the basis of light transmission figures obtained by subjecting each solution to a conventicnai type quartz spectrophotometer, the

ill

curve for the mixed solution occurs considerably to the right of the curves for the unmixed solutions, and substantially to the right of the calcu-- lated curve for such mixed solution. This deviation from the expected curve can only be explained by formation of a definite complex compound of titanium and antimony within the solution which prevents the antimony from behaving in its normal and expected manner.

As above outlined, this invention provides for the flash-proofing of high pile fabrics and particularly those made from cellulosic solutions, as by the viscose operation. When producing flashproofed viscose fabrics, no changes are needed in the process up until the time the fabric is produced, as the treatment is well-suited for the production of flame-proofed articles from flat woven viscose textiles. It is of course possible to treat threads and fibers or even sheeted cellulosic structures such as transparent cellulosic films, but the invention is particularly applicable to fabrics intended for the production of high pile textiles, since this line of goods is in the greatest need for modification. The process is also useful in fire-proofing or flame-proofing cotton materials, ilat viscose and other forms of regenerated cellulose, and cellulosic compounds such as acetate rayon. All such materials have a cellulosic base, and accordingly the invention is to be regarded as useful in the treatment of fabric material having this cellulosic base, regardless of whether it is a woven fabric or a sheet fabric.

While preferably and to obtain optimum bene-. fits under the invention, the textile or fabric under treatment is immersed directly in a monobasic acid solution containing our titanium-antimony complex, alternatively such textile or fabric may be impregnated with a titanium chloride solution as the first step in the treating process, after which the impregnated cloth, without drying, is immersed in the antimony solution. Thereafter, the subequent neutralization and washing treatments can be resorted to. While this method of treatment will afford flameproofing, the process is readily carried out and more effective results obtain when the cloth is subjected to treatment directly with the titaniumantimony complex solution. In this case, a single immersion of the goods or fabric in the acidreacting solution is had and the after-treatment with alkali and scrubbing in soap solution is likewise' simplified.

The mechanism of the treatment is not completely understood; but it is believed that the titanium is enabled to cling to the hydroxyl groups of the cellulose and become insolubilized thereby. The antimony may cling to the-cellulose as well, or to the adhering titanium, but the point is not at present well understood or deflnitely ascertainable. One thing is certain, the flame-proofing of such fabrics is effectively realized, and there is provided a process for the manufacture of pile viscose fabrics, which may be used for the making of attractive garments having great consumer appeal. The herein-contemplated treatment gives fabrics which pass the exacting A. A. T. C. C. test, but a treatment by any one of the reagents alone will not give such result. It is essential that titanium be present and that preferably it comprises the major constituent, i. e., is at least 50% of the weight of the combined oxides used.

In addition to imparting flame-proofing characteristics to a textile material, our contemplated treatment also renders such material exceeding 2 and the weight ratio of titanium to Y antimony ranging up to 10.

2. A flame-proofing solution for cellulosic substances comprising an aqueous solution of titanium and antimony in hydrochloric acid, said solution containing at least 25 g./l. of the combined oxides of titanium and antimony, with the atom ratio of antimony to titanium not exceeding 2 and the weight ratio of titanium to antimony ranging up to 10.

3. A flame-proofing solution for cellulosic substances comprising an aqueous solution of titanium and antimony in hydrochloric acid, said solution containing from 25 to 500 g./l. of the combined oxides of titanium and antimony, with the atom ratio of antimony to titanium not exceeding 2 and the weight ratio of titanium antimony ranging up to 10.

4. A flame-proofing solution for cellulosic textile material comprising an aqueous solution of titanium and antimony chlorides, said solution containing at least 25 g./l. of the combined oxides of titanium and antimony, and having an atom ratio of antimony to titanium not exceeding 2 and a weight ratio of titanium .to antimony ranging up to 10.

5. A flameprooflng solution for cellulosic textile material comprising an aqueous solution of titanium and antimony in hydrochloric acid, said solution containing from 200-400 g./l. of the combined oxides of titanium and antimony, with the atom ratio of antimony to titanium not exceeding 2 and the weight ratio of titanium to antimony ranging up to 10.

FRANK WESLEY LANE.

WILLIAM LEONARD DILLS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 723,088 Warr Mar. 17, 1903 1,501,895 Andrews et al.' July 22, 1924 1,648,433 White Nov. 8, 1927 1,996,089 Thompson Apr. 2, 1935 2,036,862 Dreyfus Apr. 7, 1936 2,095,028 Craik Oct. 5, 1937 2,147,056 Platt et a1 Feb. 14, 1939 2,310,128 Smith Feb. 2, 1943 2,395,922 Timmons Man-5, 1946 2,416,447 Laughlin et al. Feb. 25, 1947 2,427,997 White Sept. 23, 1947 FOREIGN PATENTS Number Country Date 9,556 Great Britain of 1901 312.301 Germany Jan. 14, 1922 OTHER REFERENCES Emphraim, Inorganic Chemistry, 14th ed.

(1943), Nordeman Pub. (20., N. Y., pages 331 and 756. 

1. A FLAME-PROOFING SOLUTION FOR CELLULOSIC SUBSTANCES COMPRISING AN AQUEOUS SOLUTION OF TITANIUM AND ANTIMONY IN AN INORGANIC MONOBASIC ACID, SAID SOLUTION CONTAINING AT LEAST 25 G./L. OF THE COMBINED OXIDES OF TITANIUM AND ANTIMONY, WITH THE ATOM RATIO OF ANTIMONY TO TITANIUM NOT EXCEEDING 2 AND THE WEIGHT RATIO OF TITANIUM TO ANTIMONY RANGING UP TO
 10. 